when designing EO RNP procedures, turns are limited to 5° bank angle.
Can you cite a relevant document/Standard for perusal, please ? 5 degree bank would be very difficult to sign off on due to
(a) piloting difficulty unless it be autoflight
(b) the huge turn radius and flight path wind sensitivity for skirting nasty obstacles ...
15 degree turns are the norm for EO escape path planning. Generally one would only call up lesser bank in the case of an awkward obstacle on the inside of the turn .. and then only with a positive fix co-ordinate to commence the turn.
All these matters can be addressed with modern nav system capability .. but that infers considerable planning behind the procedure.